Nonalcoholic fatty liver disease - A multisystem disease?

Abstract

Non-alcoholic fatty liver disease (NAFLD) is one of the most common comorbidities associated with overweight and metabolic syndrome (MetS). Importantly, NAFLD is one of its most dangerous complications because it can lead to severe liver pathologies, including fibrosis, cirrhosis and hepatic cellular carcinoma. Given the increasing worldwide prevalence of obesity, NAFLD has become the most common cause of chronic liver disease and therefore is a major global health problem. Currently, NAFLD is predominantly regarded as a hepatic manifestation of MetS. However, accumulating evidence indicates that the effects of NAFLD extend beyond the liver and are negatively associated with a range of chronic diseases, most notably cardiovascular disease (CVD), diabetes mellitus type 2 (T2DM) and chronic kidney disease (CKD). It is becoming increasingly clear that these diseases are the result of the same underlying pathophysiological processes associated with MetS, such as insulin resistance, chronic systemic inflammation and dyslipidemia. As a result, they have been shown to be independent reciprocal risk factors. In addition, recent data have shown that NAFLD actively contributes to aggravation of the pathophysiology of CVD, T2DM, and CKD, as well as several other pathologies. Thus, NAFLD is a direct cause of many chronic diseases associated with MetS, and better detection and treatment of fatty liver disease is therefore urgently needed. As non-invasive screening methods for liver disease become increasingly available, detection and treatment of NAFLD in patients with MetS should therefore be considered by both (sub-) specialists and primary care physicians.

Keywords: Nonalcoholic fatty liver disease, Metabolic syndrome, Diabetes mellitus type 2, Cardiovascular disease, Chronic kidney disease, Multisystem disease

Core tip: Given the increasing worldwide incidence of obesity and metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease. Recent developments in the field have shown that NAFLD not only is a “liver disease” but also is the underlying cause of an increasing number of extrahepatic manifestations; thus, it should be treated as a multisystem disease. NAFLD is most prominently linked to chronic kidney disease, mellitus type 2 and cardiovascular disease, as well as a number of other severe chronic diseases. These findings demonstrate that NAFLD ranks amongst the most serious public health problems of our time.